Web spreader



E. WARNER .May 2, 1944.

WEB SPREADER Filed Aug. 25, 1941 INVENTOR BY 6 M W fiq Patented May 2,1944 wan srmzanna Edgar Warner, Middletown, Ohio. assignor to TheChampion Paper and Fibre Company, Hamilton, Ohio, a corporation of OhioApplication August 25, 1941, Serial No. 408,226

(Cl. Til-2.1)

llclaims.

This invention relates to the handling of paper or other material in webform, whether in machines for fabricating, treating, rewindinprocessing, or using such material. In passing into or through suchmachines the webs often exhibit a tendency to be drawn into longitudinalwrinkles which frequently interfere with the processing of the web orbecome pressed into damaging creases which may even split the web inplaces.

In the eifort to prevent the formation of injurious wrinkles, variousexpedients have in the past been used either alone or in combination.Rollers over which the webs pass have often been placed closer togetherthan otherwise necessary in order to shorten the draw or unsupportedlength of web between rollers. The rollers have frequently been providedwith a crown or enlarged diameter in the central portion, and sometimeswith herringbone ridges which tend to work the wrinkles that form,outward to the edges of the web, but in spite of all known expedients,trouble with wrinkles still persists.

The present invention has for its primary object to provide a simple,novel, and more effective means of maintaining travelling webs in awrinkle-free condition. Other and more detailed objects of the inventionwill become apparent in the course of the following description.

I have discovered that when a freely rotating roller means frictionallyengages the surface of a moving web, if allowed to orient itself byswinging around a pivotal axis substantially perpendicular to thesurface of the web (and spaced from the roller means in a direction suchthat the moving web passes said'axis before passing said roller means),the roller means will assume a position in which the axis of rollerrotation is perpendicular to the direction of travel of the web. I havefurther discovered that when the roller means has assumed the positiondescribed it will resist with considerable force any effort to displaceit therefrom. On the basis of these discoveries, I have found that ifsuch a roller means is provided at each edge of a moving web and forcesare applied thereto, tending to pull them outwardly off of the edges ofthe web, these forces will be transmitted to the web, causing a lateraltension therein which serves to pull out the wrinkles and flatten theweb without causingany injury thereto. It is necessary that theengagement between the roller means and the web be frictional, and tothat end the roller means is advantageously, though not necessarily,made of or surfaced with a frictional material such as rubber, cork,felt, etc. In order that the required friction be developed there mustbe pressure between the web and the roller means. This pressure can beobtained from the tension in the web, if the web is caused to wraparound the roller means. Any material degree of wrap is.

' however, disadvantageous when, as here, the

roller means does not extend across the full width of the web. Itherefore find it convenient to secure the needed pressure by the use ofa pressure member in connection with the roller means, or by suctionfrom within a pervious surfaced roller means.

The invention will be further described with reference to theaccompanying drawing, in which:

Fig. 1 is a somewhat diagrammatic view showing a part of a web with thespreading devices of the present invention applied thereto.

Fig. 2 is a view as seen from the right hand side of Fig. 1, of thedevices shown therein, except that the roller means on the right handside of Fig. 1 has been removed in order to more clearly show that onthe left.

Fig. 3 is an end view of the web passing through the devices illustratedin Figs. 1 and 2.

Fig. 4 is a fragmentary view showing an alternative type of roller meanson the left hand edge of a web.

Fig. 5 is a sectional view of the roller means shown in Fig. 4 and takenon line 5-5 of Fig. 4.

Fig. 6 is a view of another alternative type of roller means, as seenfrom the same viewpoint as is that shown in Fig. 2.

Fig. 7 is a view of still another alternative form as seen from the samepoint of view.

Referring first to Figs. 1, 2 and 3, the web I0 is shown moving in thedirection of the arrows. The rollers H and I 2, which are narrowrelative to the width of the web, are in frictional engagement with theright and left hand edges of the web, respectively. These rollers areadvantageously covered with rubber or other resilient frictional covers,and are mounted to rotate freely on their respective axes l3 and H. Thefrictional contact of the web with these rollers is maintained, in theembodiment illustrated in Figs. 1, 2 and 3, by means of similar rollersl5 and I6 (which, though they may conveniently be of the same diameteras rollers II and I2, are illustrated in Fig. l as slightly smaller, inorder that rollers II and I2 may not be completely concealed thereby).In general the resiliency of the coverings of rollers ll, I2, I5 and Itserves to provide the pressure necessary to'give the required frictionalcontact with the web. If sllfliciently resilient roller coverings arenot used, resilient or spring mountings of known types may be providedfor causing the necessary pressure of rollers l5 and 19 against rollersII and 12 respectively.

The roller pairs ll, 19 and l2, l9 are rigidly mounted on arms 2! and22, respectively, which direction of movement of the web from theirrespective pivots. The pivots are conveniently, though not necessarily,located beyond-the edges of the web, as illustrated in Figs. 1, 2 and 3.The spreading forces are applied 'to roller pairs ll, l5 and l2, l9 byany suitable means. Advantageously, flexible cords 29 and are attachedto arms 2i and 22, thence pass over pulleys 21 and 28 and carry weights29 and 30, respectively, which tend to pull the rollers off of the edgesof the web. As has already been noted, the motion of the web creates astrong tendency for the rollers to swing on their pivots and assume theposition shown in the drawing, wherein their axes of rotation areperpendicular to the direction of travel of the web. They stronglyresist displacement by forces such as those exerted by weights 29 and 30through cords 25 and 29, and these forces thus create a lateral tensionin the web which tension removes, or prevents the formation of, thetroublesome longitudinal wrinkles. The weights 29 and 30, or anyalternative forceexerting-means which may be used, are advantageouslyadjustable to permit adjustment of the tension to the degree required tomaintain the travelling web in an unwrinkled condition. The weights onthe opposite sides are, however, advantageously equal, as the web isthereby tensioned and spread equally. This serves to automaticallycompensate for any" differences in the hardness, resiliency, or slippageof the rolls on opposite sides, which might otherwise causean unequalpulland actually draw -wrinkles into the web instead of preventing theirformation.

When the web It comes t an end, the weights 29 and "swing arms 2| and 22outward to the limits of their motion, advantageously carrying theroller pairs ll, i5 and l2, l9 out of the path of the web II. A new webcan therefore be threaded through without interference from the rollers.It is then only necessary to push them inward manually until they engagethe edge of the moving web and they will automatically travel inward totheir working positions.

Figs. 4 and 5 illustrate a modified form of the devices of the presentinvention, designed to adapt it for use with webs which have beenfreshly coated,printed, etc. on one side and which therefore must not bepassed between press rolls such as illustrated in Figs. 1, 2 and 3. Onlythe roller means ll on one edge of the web is illustrated, that on theother edge of the web being constructed in the same manner butoppositely mounted. Instead of a press roll to insure frictionalengagement of the web with the roll, the roll ll is provided with aperforate or pervious outer rotating shell 42 and a stationary internalsuction box I! which communicates by means of a hollow shaft I4 andflexible conduit 49 with any suitable suction device of known type, notshown. Suction rolls of this type are .well known in the art and willnot be further described. This roll is mounted on arm 9! which isadapted to swing freely on fixed pivot 92.

Since this device is all on on side of the web, the pivot 92 need not belocated beyond the edge of the web but,

if desired, may readily be located within the width of the web, asshown. It may or may not be opposite the middle of the roller but must,as

before described, be so disposed with reference to the roller II thatthe moving web passes the pivot 92 before reaching roller 4|. Forcetending to pull the roller means away from the edge of the web isapplied as before, conveniently by means of cord 99 passing over pulley91 and supporting weight 59. The device functions in the same manner asthat illustrated in Figs. 1, 2 and 3 to apply lateral tension to thetravelling web and thereby maintain it in a wrinkle-free condition. Itis further possible with this modification to limit the swing, byconventional means not shown, sufficiently to prevent the rollers frombeing pulled beyond the edges of the path of the web, since the rollers,being on one side only of the web, cannot interfere with threading.Immediately after threading, movement of the web will automatically drawthe arms with the rollers into their operating positions.

Fig. 6 shows another modified structure. This, like that just described,depends upon suction to insure frictional engagement between the rollermeans and the web, so that it may operate on a web, one side of whichcarries wet ink, coating, or other matter which may not contact a solidsurface. In order to give a longer are of contact with the web than isobtained with the suction roll shown in Figs. 4 and 5, the roller meansis here made in the form of a known type of "suction apron or suctionbeltan endless pervious or perforate band 9|, which passes around freelyturning rollers 92, 99 and-over a suction box 94 wherein a partialvacuum is maintained byexhaust through flexible conduit 95., Thisconstitutes the element of difference from the previously describedstructure. The supporting arm 99 and fixed pivot 91 are essentially thesame in all cases. The same is true of the flexible cord 59 and weight59 not shown in Fig. 6. The principles and mode of operation are alsoessentially the same as in the other modifications and will not befurther described.

Fig. "I shows a further modified structure. This structure, like thatshown in Figs. 1, 2 and 3, depends on a pressure member on the oppositeside of the web to assure the necessary frictional engagement of the webwith the roller means. The roller means II is provided with africtional, advantageously resilient surface, and rotates freely on axis12. The opposite surface of web 19 is supported on a rigid, smooth,advantageously polished metallic surface 13 which preferably extendsacross the full width of the web. This surface may be flat, convex. orthe surface of a relatively large diameter roll. The pressure necessaryfor the required frictional engagement may be provided by the resilienceof the roll II, or separate spring means of known type may be used ifdesired. The roller means is carried on arm II which swings freely onpivot 11 in response to the action of the moving web and of the weight29 acting through cord 29 (not shown in Fig. 7). The device functionsinthe manner described with reference to the other Mums, and thedescription will therefore not'be repeated here.

The present invention is thus seen to char a I simple, reliable, easilycontrolled, and effective method of maintaining travelling web! in asmooth and wrinkle-free condition. It is of particular value where websof paper, fabr-ic, etc. are drawn under tension into press rolls,calender rolls, roll winding devices, coating or printing devices, orthe like, where wrinkles become.

ond and similar pair of rollers oppositely mounted and similarlyengaging the web near the opposite edge thereof; each of said pairs ofrollers being mounted and adapted to swing freely on a pivot located ata material distance, in the direction from which the web is travelling,from the axes of roller rotation, said pivot being substantiallyperpendicular to the plane of the web, whereby said rollers tend, byvirtue of their engagement with the moving web, to orient themselves byswinging on their respective pivots, and thereafter to maintain theiraxes of rotation at right angles to the direction of travel of the web;and means for exerting oppositely directed and substantially equalforces on each of said pairs of rollers, in directions tending to pullthem off of the edges of the web.

2. In a device for applying lateral tension to a travelling web: a pairof rollers engaging the web for a short distance inward from one edgethereof; a second pair of rollers engaging the web for a short distanceinward from the opposite edge thereof; each of said pairs of rollersbeing mounted and adapted to swing freely on a pivot located at amaterial distance, in the direction from which the web is travelling,from the axes of roller rotation, said pivot being substantiallyperpendicular to the plane of the web, whereby said rollers tend, byvirtue of their engagement with the moving web, to maintain their axesof rotation at right angles to the direction of travel of the web; andmeans for exerting forces on said pairs of rollers, in directionstending to pull them ofi of the edges of the web.

3. In a device for applying lateral tension to a travelling web: rollermeans frictionally en-' gaging one edge thereof; separate roller meansfrictionally engaging the opposite edge thereof; both of said rollermeans being narrow relative to the width of the web, having axes ofrotation approximately. parallel to the plane of the web, and each-beingmounted to swing freely around a pivot substantially normal to the planeof the web and a material distance, in the direction from which the webis travelling, from the axes of the roller means; and means for exertingforces on each of said roller means tending to swing said roller meansabout their respective pivots in directions away from the center line ofthe web.

4. In a device for applying lateral tension to a travelling web: rollermeans frictionally engaging the web near one edge thereof, said rollermeans being narrow relative to the width of the web, having an axis ofrotation approximately parallel to the plane of the web, and beingmounted to swing freely around a'pivot substantially normal to the planeof the web, and

spaced a material distance, in the direction from which the web istravelling, from the axis of rotation of said roller means: and meansforexerting force on said roller means tending toswing said roller meansaround said pivot and oil of the edge of the web.

5. A device for providing lateral tension in a moving web, comprising:separate roller means engaging opposite edges of the web; means forholding the web in frictional engagement with said roller means;separate pivots, substantially normal to the plane of the web, on whichsaid roller means are separately mounted, and about which they may swingfreely, said roller means being disposed in the general direction ofmovement'of the web from their respective pivots; and means for applyingforces to said roller means tending to swing them, around theirrespective pivgts, in directions away from the axis of the we 6. Adevice for providing lateral tension in a moving web, comprising:separate roller meansengaging opposite edges of the web; a pressuremember, engaging the opposite side of the web, for holding the web infrictional engagement with said roller means; separate pivots,substantially normal to the plane of the web, on which said roller meansare separately mounted, and about which they may swing freely, saidroller means being disposed in the general direction of movement of theweb from their respective pivots: and means for applying forces to saidroller means tending to swing them, around their respective pivots, indirections away from the axis of the web.

7. A device for providing, lateral tension in a moving web, comprising:separate roller means engaging opposite edges of the web, each of saidroller means being provided with a pervious webengaging surface; meansfor maintaining a partial vacuum inside the pervious surface engagingthe web, on each of said roller means, whereby the web is held, bysuction, in frictional engagement with said roller means; separatepivots, substantially normal to the plane of the web, on which saidroller means are separately mounted, and about which they may swingfreely, said roller means being disposed in the general direction ofmovement of the web, from their respective pivots; and means forapplying forces to said roller means tending to swing them, around their-respective pivots, in directions away from the axis of the web.

8. A device for providing lateral tension in a moving web, comprising:separate roller means engaging opposite edges of the web; a pivot,substantially normal to the plane of the web, on which each of saidroller means is mounted for a free swinging movement, said roller meansbeing disposed in the general direction of movement of the web fromtheir respective pivots and means for applying force to said rollermeans tending to swing them, around their respective pivots, indirections away from the axis of the web.

9. In a device for maintaining a moving web in a wrinkle-free condition:separate roller means adapted to frictionally engage the moving web fora fraction of its width, near the opposite edges thereof, and tending,by virtue of their engagement with the moving web, to maintain apredetermined distance therebetween; and means for applying separatingforces to said roller means which forces are, by virtue of theengagement of the roller means with the web, transferred to the web asspreading forces which constitute lateral tension in. the web.

4 asaaioa web between said Slipping means.

l1. Method oi maintaining a section of a moving web in a wrinkle-freecondition, which comprises subiecting each of the opposite edges of theweb to a rolling action, at a fixed location in the path of travel ofthe web; balancing the lateral tension in the web at this locationagainst a predetermined mechanical force: and continuously adjusting thedirections '01 said rolling actionsJn accordance with said balance,thereby maintaining a predetermined substantially conl0 stant lateraltension in the web in said location.

EDGAR WARNER.

